kubernetes-the-hard-way/docs/05-kubernetes-configuration-files.md

# Generating Kubernetes Configuration Files for Authentication

In this lab you will generate [Kubernetes configuration files](https://kubernetes.io/docs/concepts/configuration/organize-cluster-access-kubeconfig/), also known as kubeconfigs, which enable Kubernetes clients to locate and authenticate to the Kubernetes API Servers.

## Client Authentication Configs

In this section you will generate kubeconfig files for the `controller manager`, `kubelet`, `kube-proxy`, and `scheduler` clients and the `admin` user.

### Kubernetes Public IP Address

Each kubeconfig requires a Kubernetes API Server to connect to. To support high availability the IP address assigned to the  load balancer will be used. In our case it is `192.168.5.30`

```
LOADBALANCER_ADDRESS=192.168.5.30
```

### The kube-proxy Kubernetes Configuration File

Generate a kubeconfig file for the `kube-proxy` service:

```
{
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.crt \
    --embed-certs=true \
    --server=https://${LOADBALANCER_ADDRESS}:6443 \
    --kubeconfig=kube-proxy.kubeconfig

  kubectl config set-credentials system:kube-proxy \
    --client-certificate=kube-proxy.crt \
    --client-key=kube-proxy.key \
    --embed-certs=true \
    --kubeconfig=kube-proxy.kubeconfig

  kubectl config set-context default \
    --cluster=kubernetes-the-hard-way \
    --user=system:kube-proxy \
    --kubeconfig=kube-proxy.kubeconfig

  kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
}
```

Results:

```
kube-proxy.kubeconfig
```

### The kube-controller-manager Kubernetes Configuration File

Generate a kubeconfig file for the `kube-controller-manager` service:

```
{
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.crt \
    --embed-certs=true \
    --server=https://127.0.0.1:6443 \
    --kubeconfig=kube-controller-manager.kubeconfig

  kubectl config set-credentials system:kube-controller-manager \
    --client-certificate=kube-controller-manager.crt \
    --client-key=kube-controller-manager.key \
    --embed-certs=true \
    --kubeconfig=kube-controller-manager.kubeconfig

  kubectl config set-context default \
    --cluster=kubernetes-the-hard-way \
    --user=system:kube-controller-manager \
    --kubeconfig=kube-controller-manager.kubeconfig

  kubectl config use-context default --kubeconfig=kube-controller-manager.kubeconfig
}
```

Results:

```
kube-controller-manager.kubeconfig
```


### The kube-scheduler Kubernetes Configuration File

Generate a kubeconfig file for the `kube-scheduler` service:

```
{
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.crt \
    --embed-certs=true \
    --server=https://127.0.0.1:6443 \
    --kubeconfig=kube-scheduler.kubeconfig

  kubectl config set-credentials system:kube-scheduler \
    --client-certificate=kube-scheduler.crt \
    --client-key=kube-scheduler.key \
    --embed-certs=true \
    --kubeconfig=kube-scheduler.kubeconfig

  kubectl config set-context default \
    --cluster=kubernetes-the-hard-way \
    --user=system:kube-scheduler \
    --kubeconfig=kube-scheduler.kubeconfig

  kubectl config use-context default --kubeconfig=kube-scheduler.kubeconfig
}
```

Results:

```
kube-scheduler.kubeconfig
```

### The admin Kubernetes Configuration File

Generate a kubeconfig file for the `admin` user:

```
{
  kubectl config set-cluster kubernetes-the-hard-way \
    --certificate-authority=ca.crt \
    --embed-certs=true \
    --server=https://127.0.0.1:6443 \
    --kubeconfig=admin.kubeconfig

  kubectl config set-credentials admin \
    --client-certificate=admin.crt \
    --client-key=admin.key \
    --embed-certs=true \
    --kubeconfig=admin.kubeconfig

  kubectl config set-context default \
    --cluster=kubernetes-the-hard-way \
    --user=admin \
    --kubeconfig=admin.kubeconfig

  kubectl config use-context default --kubeconfig=admin.kubeconfig
}
```

Results:

```
admin.kubeconfig
```


##

## Distribute the Kubernetes Configuration Files

Copy the appropriate `kubelet` and `kube-proxy` kubeconfig files to each worker instance:

```
for instance in worker-1; do
  scp ${instance}.kubeconfig ${instance}:~/
done
```

```
for instance in worker-1 worker-2; do
  scp kube-proxy.kubeconfig ${instance}:~/
done
```

Copy the appropriate `kube-controller-manager` and `kube-scheduler` kubeconfig files to each controller instance:

```
for instance in master-1 master-2; do
  scp admin.kubeconfig kube-controller-manager.kubeconfig kube-scheduler.kubeconfig ${instance}:~/
done
```

Next: [Generating the Data Encryption Config and Key](06-data-encryption-keys.md)